The purpose of this research study is to evaluate a new, experimental drug called Flocor in patients with sickle cell disease. In sickle cell disease, blood flow in the body is impaired by sickled cells that stick to each other and to the inside of the blood vessels. Sickle cell pain is usually a result of inadequate blood flow to a certain area of the body. Flocor is a liquid drug that improves blood flow in all areas of the body by making the blood less sticky. In this study, we hope to determine if this drug helps to shorten the duration of sickle cell crisis and if it decreases the need for pain medications. This drug has been studied in about 3000 patients with heart attacks and about 50 patients with sickle cell disease. The study in sickle cell patients suggested that Flocor decreases pain and duration of painful crisis, but it was a small study and no firm conclusions about benefit could be made.